to the site of the altar that he had built there at first; and there Avram invoked Hashem by name.
Classic midrash (return to the first altar)
English: To the site of the altar that he had made there at first — he returned to the place of his first prayer. This teaches that fixedness in the place of prayer is beloved.
Supplementary classical material not listed by Torah Temimah under this exact passuk.